Set accurate value for alwaysThrottleRetries on www (#32684)

This flag value was updated in
https://github.com/facebook/react/pull/28965 (seemingly unrelated, maybe
as part of unit testing). But its still controlled by a dynamic flag in
www. Let's update this to VARIANT to accurately represent the state of
the rollout.

Before:
<img width="1340" alt="Screenshot 2025-03-20 at 10 45 30 AM"
src="https://github.com/user-attachments/assets/d0405a36-eb71-4108-9e23-8d462cc68fb4"
/>

After:
<img width="1351" alt="Screenshot 2025-03-20 at 10 45 11 AM"
src="https://github.com/user-attachments/assets/459d260d-7a25-430b-95a6-d6a91d958417"
/>